13482-22-9Relevant articles and documents
One-pot Synthesis of 4-Aminocyclohexanol Isomers by Combining a Keto Reductase and an Amine Transaminase
Sviatenko, Olha,Ríos-Lombardía, Nicolás,Morís, Francisco,González-Sabín, Javier,Venkata Manideep, Kollipara,Merdivan, Simon,Günther, Sebastian,Süss, Philipp,H?hne, Matthias
, p. 5794 - 5799 (2019)
The efficient multifunctionalization by one-pot or cascade catalytic systems has developed as an important research field, but is often challenging due to incompatibilities or cross-reactivities of the catalysts leading to side product formation. Herein we report the stereoselective preparation of cis- and trans-4-aminocyclohexanol from the potentially bio-based precursor 1,4-cyclohexanedione. We identified regio- and stereoselective enzymes catalyzing reduction and transamination of the diketone, which can be performed in a one-pot sequential or cascade mode. For this, we identified regioselective keto reductases for the selective mono reduction of the diketone to give 4-hydroxycyclohexanone. The system is modular and by choosing stereocomplementary amine transaminases, both cis- and trans-4-aminocyclohexanol were synthesized with good to excellent diastereomeric ratios. Furthermore, we identified an amine transaminase that produces cis-1,4-cyclohexanediamine with diastereomeric ratios >98 : 2. These examples highlight that the high selectivity of enzymes enable short and stereoselective cascade multifunctionalizations to generate high-value building blocks from renewable starting materials. Introduction.
Ionic liquids based on the 7-azabicyclo[2.2.1]heptane skeleton: Synthesis and properties
De Vos, Nils,Maton, Cedric,De Vreese, Peter,Brooks, Neil R.,Binnemans, Koen,Stevens, Christian V.
, p. 3741 - 3750 (2013)
Based on a previously developed method for the synthesis of epibatidine analogues, a series of new ionic liquids, based on the 7-azabicyclo[2.2.1] heptane skeleton, have been synthesized. The chemical and physical properties of the ionic liquids with bis(trifluoromethylsulfonyl)imide (Tf2N) and dicyanamide [N(CN)2] anions were investigated and they were found to exhibit very good electrochemical and thermal stabilities. Ionic liquids with the cationic part based on the structure of epibatidine (a 7-azabicyclo[2.2.1] skeleton) have been prepared. The chemical and physical properties of these ionic liquids with dicyanamide and bis(trifluoromethylsulfonyl)imide anions were investigated and they were found to show very good electrochemical and thermal stability. Copyright
Electron Transfer Induced Desilylation of Trimethylsilyl Enol Ethers
Gassman, Paul G.,Bottorff, Kyle J.
, p. 1097 - 1100 (1988)
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Radlick,Crawford
, p. 1669 (1972)
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Palladium(0) Catalyzed Reaction of 1,4-Epiperoxides. Conversion of a Prostaglandin Endoperoxide to Primary Prostaglandins
Suzuki, M.,Noyori, R.,Hamanaka, N.
, p. 5606 - 5607 (1981)
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NMR spectroscopic conformational analysis of 4‐methylene‐ cyclohexyl pivalate—the effect of sp2 hybridization
Kleinpeter, Erich,Heydenreich, Matthias,Koch, Andreas,Krtitschka, Angela,Krüger, Tobias,Linker, Torsten
, p. 1073 - 1078 (2017)
The conformational equilibrium of the axial/equatorial conformers of 4‐methylene ‐cyclohexyl pivalate is studied by dynamic NMR spectroscopy in a methylene chloride/freon mixture. At 153 K, the ring interconversion gets slow on the nuclear magnetic resonance timescale, the conformational equilibrium (?ΔG°) can be examined, and the barrier to ring interconversion (ΔG#) can be determined. The structural influence of sp2 hybridization on both ΔG° and ΔG#of the cyclohexyl moiety can be quantified.
Microreactors for oxidations using fluorine
Chambers, Richard D.,Holling, Darren,Rees, Anthony J.,Sandford, Graham
, p. 81 - 82 (2003)
Continuous flow gas-liquid thin film microreactors have been effectively used for the oxidation of alcohols and Baeyer-Villiger oxidation of ketones using elemental fluorine.
Trans-Selective and Switchable Arene Hydrogenation of Phenol Derivatives
Bergander, Klaus,Glorius, Frank,Heusler, Arne,Wollenburg, Marco
, p. 11365 - 11370 (2020/11/24)
A trans-selective arene hydrogenation of abundant phenol derivatives catalyzed by a commercially available heterogeneous palladium catalyst is reported. The described method tolerates a variety of functional groups and provides access to a broad scope of trans-configurated cyclohexanols as potential building blocks for life sciences and beyond in a one-step procedure. The transformation is strategically important because arene hydrogenation preferentially delivers the opposite cis-isomers. The diastereoselectivity of the phenol hydrogenation can be switched to the cis-isomers by employing rhodium-based catalysts. Moreover, a protocol for the chemoselective hydrogenation of phenols to cyclohexanones was developed.
Hydrogenation of Phenol to Cyclohexanone over Bifunctional Pd/C-Heteropoly Acid Catalyst in the Liquid Phase
Liu, Shiwei,Han, Jing,Wu, Qiong,Bian, Bing,Li, Lu,Yu, Shitao,Song, Jie,Zhang, Cong,Ragauskas, Arthur J.
, p. 2383 - 2389 (2019/06/19)
Abstract: Cyclohexanone is an important intermediate in the manufacture of polyamides in chemical industry, but direct selective hydrogenation of phenol to cyclohexanone under mild conditions is a challenge. Hydrogenation of phenol to cyclohexanone has been investigated in the presence of the composite catalytic system of Pd/C-heteropoly acid. 100% conversion of phenol and 93.6% selectivity of cyclohexanone were achieved within 3?h under 80?°C and 1.0?MPa hydrogen pressure. It has been found that a synergetic effect of Pd/C and heteropoly acid enhanced the catalytic performance of the composite catalytic system which suppressed the hydrogenation of cyclohexanone to cyclohexanol. Graphic Abstract: [Figure not available: see fulltext.].
